Metamath Proof Explorer


Theorem sltaddpos2d

Description: Addition of a positive number increases the sum. (Contributed by Scott Fenton, 15-Apr-2025)

Ref Expression
Hypotheses sltaddpos.1 φ A No
sltaddpos.2 φ B No
Assertion sltaddpos2d φ 0 s < s A B < s A + s B

Proof

Step Hyp Ref Expression
1 sltaddpos.1 φ A No
2 sltaddpos.2 φ B No
3 0sno 0 s No
4 3 a1i φ 0 s No
5 4 1 2 sltadd1d φ 0 s < s A 0 s + s B < s A + s B
6 addslid B No 0 s + s B = B
7 2 6 syl φ 0 s + s B = B
8 7 breq1d φ 0 s + s B < s A + s B B < s A + s B
9 5 8 bitrd φ 0 s < s A B < s A + s B